Flexible couplings are well known devices used for providing a driving connection between power sources such as a motor with mechanisms to be driven such as a pump or a gear reduction unit and like systems. Such drive couplings have the capability of accommodating reasonable degrees of non-alignment between the shaft members that are interconnected and to permit substantially trouble free operation over extended periods of time.
One common type of flexible drive coupling utilizes gear elements that are interconnected by a flexible spacer or coupling element. This element may be a molded plastic article of sufficient rigidity to transmit driving force but having sufficient flexibility to accommodate a certiin degree of flexing during rotation. Such an element is provided with gear sections that are adapted to mesh respectively with the driving and the driven gear elements.
In such a system, the motor or power source and the driven element such as a pump are normally separate housings in adjacent or close proximity to one another and mounted in fixed positions on a predetermined fixed special relationship to one another. The gear elements mounted on shafts respectively projecting from the respective housings are in turn secured on the shafts in a fixed position in a predetermined special relationship to one another determined by the physical dimensions of the spacer or coupling element that is mounted in operative position connecting the two gear members. The fixed relationship of the two housings may be accomplished by mounting them each on a fixed bed or by interconnecting the housings by a structural mounting frame. In some instances, one of the housings may be rigidly supported on a base and the other housing supported thereon by the structural mounting frame.
In drive assemblies of this kind, problems have arisen as a result of the exposed drive coupling elements. In many instances, for example, the drive assembly may be utilized in an environment characterized by the presence of dust or other particles that might be injurious to the interconnected drive coupling or where there may be water or other liquids present which could have a detrimental effect if permitted to come into contact with the coupling elements. A further aspect of the exposure to the surroundings of such drive elements arises from the more recently developed stringent standards of the Occupational Safety and Health Administration (OSHA) under which such exposed power transmission mechanisms are considered to be a potential hazard to workers. Unless properly protected such moving elements could cause injury should the worker accidentally come into contact with it.
A relatively obvious solution to these problems is to provide an enclosure or a shroud member surrounding the rotating elements projecting between the housings of the motor and mechanism that is driven thereby. The problem with such a solution however, is that such complete enclosure of the drive coupling elements prevents access to the elements while the housings and the intervening surrounding shroud member are being assembled. Such access is necessary and is conventionally relied upon to place the engaging elements of the coupling in aligned and engaging position as the assembly is completed. Thus the gears are usually designed so that they come into meshing engagement as the elements of the assembly are brought longitudinally toward one another during assembly. The attempts of using surrounding shroud elements such as above have resulted in requiring that this aligning adjustment be done in a "blind" manner and essentially with no external access as the parts are brought together. As a result the assembling of the parts is extremely laborious and time consuming and generally not satisfactory for practical purposes. One must consider that many such power assemblies are manufactured in substantial quantities on a production basis. The obstacles that the above construction introduces are readily apparent.
The provision of an opening or openings in the shroud which would permit external access to the coupling elements during assembly is of course not satisfactory because this defeats the very purpose of the shroud.